Well anyone can buy a second.name if second isn't already registered, and then set up their own first. subdomain, so most visitors aren't going to know the difference in between grandfathered in first.second.name sites and people who just bought second level domains and created their own subdomain.

if you're lucky, you can do something like first.sec.ond

works for many polish people who own ski resorts :)

I remember when delicious.com was just del.icio.us. I miss that site.